Handy little tip

[MikeTangas]

In the process of checking out a bad resistor end, I discovered that the power steering return line was leaking madly. All this time, I believed my steering box was the culprit. Basically, nearly 30 years of engine heat and constant fluid transfer had taken it's toll. There weren't any specific leaks, the hose material was acting like a sponge instead, with the fluid seeping through.

Stopped by my local MB tech to see if he had a replacement and his advice was to get some quality rubber hose from Pep Boys, AutoZone, etc. Said it took 5/8 ID hose, and be sure it isn't heater hose.

AutoZone had crankcase ventilation hose, but no 5/8 ID. They did however have 19/32 ID, and since that is almost 5/8, I got it. $2.00 worth of hose and 20 minutes work was all it took. I bought 2 feet but only used 20 inches for a perfect fit. Siphoning off the steering fluid before removing the hose, then siphoning out of the hose before disconnecting the far end made for a neat job. Once I removed the old hose, it was very hard and no longer flexible, and left a perfect oil print of it's outline on the garage floor. There is a hard plastic ring, which will need to be transferred to the new hose, it keeps the hose from contacting/rubbing on the sub-frame.

I'm sure many of the older Benz's currently have, or will soon have similar leakage and wanted to pass on this tip to all. A cheap easy fix, now you can't beat that with a stick.

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Mike Tangas
73 280 SEL 4.5

[Douglas Broome]

What did you do about the fittings. Mine screw into the steering box and the pump. Do yours clamp on?

[73MB280SEL]

Howdy,

I've got basically the same car as you and have the same problem. I am still concerned about power steering box leaks, but I know the hose is leaking.

Question is: My low pressure hose has standard hose clamps on it which seems a little inadequate for such a critical system. Some of the fluid is definately leaking at the clamp. How is yours attached at each end?

Sholin

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Lt. Blue 1973 MB 280 SEL (108) with sunroof and console shift.
1996 Chevy Camaro Z-28 LT1.

[MikeTangas]

The return line is low pressure therefore the hose clamps are sufficient. My return line was/is still attached with hose clamps which appear to be original. The steel stub of line that continues to the steering box is formed with two ridges to seal the hose end, and the clamps should lay between the ridges. The resevoir end has at least one ridge, possibly two as well. One mine, only the pressure side has pressed/crimped fittings.

If your hose is leaking at the ends, it is probably due to the hose being brittle and/or cracked. Mine was leaking there as well. No leakage from the hose this morning, or after a 30 mile run. Will be logging another 150 miles this afternoon and will of course check the hose condition upon returning.

Now I should be able to gauge if the steering box is leaking or just seeping a little from the seals.

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Mike Tangas
73 280 SEL 4.5

[MikeTangas]

After logging a total of 180 miles today, I checked the power steering return line after arriving home. The line had absolutely no leakage, the inner fenderwell was clean and free of steering fluid. I checked the hose at full operating temperature and it was firm, yet flexible, allowing for movement with pressure changes. Also found no evidence of seepage at the hose ends.

Prior to making the 150 mile trip, I also cleaned the inner fenderwell again, as well as all of the undercarriage and steering box I could reach. Now any fluid steering fluid loss ahould be easily traced.

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Mike Tangas
73 280 SEL 4.5

[This message has been edited by MikeTangas (edited 11-04-2000).]

[73MB280SEL]

Thanks for the info. I'll be doing this in the next few days.

Sholin

[cth350]

Just to clarify this thread...

There are two hoses and they are NOT alike.

The hose attached by clamps is just a vanilla hose that must be impervious to oil. Thus the advice for "anything but coolant hose" will do.

The hose with the metal fittings is a high pressure hose. Those fittings are attached with special tools to special hose. You can buy the bulk hose from benz and others. Getting the fittings attached can be done by any competent hydraulic hose specialist. That same specialist can probably provide the bulk hose too, saving you one mail order. But "real" mercedes hose looks like it. Vanilla hight pressure hose may not have the same look and feel.

Very bad things can happen if you try to use regular clamps on the high pressure hose.

-CTH

PS. Your transmission cooler hoses need the same care and attention from the same specialist.

[debi]

I missed something. Two hoses? Which one is the low pressure one that may need replacing? As always, I'm confused.
debi

[cth350]

Debi,

Wow, an old thread. I presume you have an old problem ?

Just eyeball the hoses at the pump & resevoir.

The hose that connects directly to the fluid resevoir is the low pressure hose. All it's doing is returning fluid. It's held on with a clamp, easily replaceable, and when you disconnected all the fluid will fall on the floor real fast.

The hose that connects to the pump is your high pressure hose. It is not all that expensive to replace (but it's not cheap).

-CTH

[Aaron]

When you open up the power steering system, don't forget to bleed the box of any air afterwards. There is an 11mm bleed screw on top of the box which you need to crack open and turn the wheel from lock to lock a few times to get the air out. The best way is to put a length of hose on the bleed nipple and run it back into the fluid resirvoir and just have an assistant turn the wheel until bubble-free fluid emerges from the end of the hose. Tighten down the bleed screw and you're set!

BTW, ATF (Dexron III) is fine for the old systems.